Reading music develops into more than just being able to see notes.
it becomes part of the sub-concious way the brain will access it to reinforce information you know or learn. It becomes one of your Musical Senses that your body taps into and uses to help you play your instrument.
Many have posted about tab being numbers, but the truth of it for me is it is still notes, as i suspect it is for many players that have musical education, or very developed through experience, intensive musical skills.
So the tab show 5 on the A string, i bet you see D as well, or you know it is a D rather than a 5.
This fact will escape players that cannot read because they will lack the experience to draw on. Since chord books use a visual reference to show how the finger can be placed so it is with tab.
On the bass because of the tuningin 4ths it lends its self well to leaning patterns. But patterns are a small part of it as they to will reinforce musical learning, especially reading. i have worked with composers who can visualize instruments in their mind as well as hear what it is they want to play when notating arrangements.
I learned to play bass in a couple of weeks, because i knew music. I was orchestrally trained, so i knew music and i could order notes. So all i done was order the notes on the fretboard and was good to go. But when i was ordering them i saw in my minds eye the staff positions of the notes. I then ' saw ' the intervals on the staff and applied them to the fretboard notes, as i did with chord tones, Arps and Scales.
The other thing that stood me in good stead was as a brass player my right hand fingers already had developed dexterity to pluck through the years of valve fingering...so i started playing three finger style without any thought or difficulty.
My piano skills, as limited as they were, enabled me to fret and move around the neck, so again i was never starting from scratch, all i had learned was used to help me play and progress on bass.
Any player working in music will benefit from any musical interaction being it tabs, theory, SN, listening and watching, or experience of another instrument..it is all taking in and used to reinforce what we already know, or will help understand and new idea we learn as we will compare it with some thing we already know. In learning we do not always need to understand certain points and teachings, just retain them as they will have a use later on.
So at the top of this post i mentioned that even though the tab would show 5th position on A string for a D, if i add 4th postion on the D string and 5th postion on the G string how many of you can not only see the notes but hear the sound they make...without looking on the neck to work it out?
This is my point, the more you learn the more your sub-concious has to draw on to come to a conclusion in helping you play and understand your instrument, whether you realise it or not. Reading music is not the whole skill, its getting it off the page and making it real so it connects with people, that is the skill.
The points made to insinuate that readers are souless or robots must then apply across the spectrum of artistic expression.
That means no-one can really play Shakespeare because the words are written for them as they cannot change them to use there own words of expression.
Actors such as Bogart, Fonda, Brando, Davis, etc were no good because the script told them what to say and a director told them what to do. Yes reading does involves total freedom of expression if you have the training, experiencem understanding and ability do do it. Yes there as those that can do it and those that can't, as in all walks of life there are different levels of ability and different demands on that ability...reading music is the same.
All any player has to do is start somewhere and build on it and develop a cumlitave knowlege and experience to draw on, then they will realise it is all the same its about how it is played, not really how it is writtenor read.